Convert CONFIG_ARP_TIMEOUT to Kconfig

This converts the following to Kconfig:
   CONFIG_ARP_TIMEOUT

Cc: Ramon Fried <rfried.dev@gmail.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/net/Kconfig b/net/Kconfig
index 2ae9d6a..683c2ad 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -8,6 +8,10 @@
 
 if NET
 
+config ARP_TIMEOUT
+	int "Milliseconds before trying ARP again"
+	default 5000
+
 config PROT_UDP
 	bool "Enable generic udp framework"
 	help
diff --git a/net/arp.c b/net/arp.c
index 0b086dc..f29b867 100644
--- a/net/arp.c
+++ b/net/arp.c
@@ -17,14 +17,6 @@
 
 #include "arp.h"
 
-#ifndef	CONFIG_ARP_TIMEOUT
-/* Milliseconds before trying ARP again */
-# define ARP_TIMEOUT		5000UL
-#else
-# define ARP_TIMEOUT		CONFIG_ARP_TIMEOUT
-#endif
-
-
 #ifndef	CONFIG_NET_RETRY_COUNT
 # define ARP_TIMEOUT_COUNT	5	/* # of timeouts before giving up  */
 #else
@@ -109,7 +101,7 @@
 	t = get_timer(0);
 
 	/* check for arp timeout */
-	if ((t - arp_wait_timer_start) > ARP_TIMEOUT) {
+	if ((t - arp_wait_timer_start) > CONFIG_ARP_TIMEOUT) {
 		arp_wait_try++;
 
 		if (arp_wait_try >= ARP_TIMEOUT_COUNT) {